Sublime Text is a code editor that comes with easy keyboard shortcuts, clean user interface, excellent performance and useful features. You even have the option to launch this editor from the command line of your Mac.

Personally, I love this editor and feel most comfortable working on it. It is free to start with, but the creators urge you to buy this editor if you plan to use it every day.

To get it, go to sublimetext.com for the current version and download it for the operating system you're using. If you plan to use Nitrous, then you don't have to download it because this editor is already built into their software. Installation is fairly simple, and you can follow the instructions here

While installing, you can even customize it to have your own shortcuts.

If you don't feel comfortable with Sublime or want to use a different editor, feel free as your choice will not affect the development environment in any way.